Yes, i have read very positive comments about these Hesi fertilizers from various different growers of the green stuff and few chili growers too, so you pretty much cant go wrong using Hesi base nutes. I just started with 40ml/10 litres of water indoor because the plants where already pretty big at that point and i did not know anything about the dosages at that time, but it worked fine either way without issues. However if i started using this stuff with seedlings and such, i would have to start using it with very mild dosages at first before i would start ramping it up to the growing dosage of course.
I have never adjusted any ph of my water thus far, but i left the water to sit around in the watering can for 24 hours before using it to mix the nutes in a separate container. I leave about one inch of the water inside the watering can unused and drain it away before filling it again with the new tapwater, because some of the crap in the tapwater will fall to the bottom of the watering can in 24 hours time. I always recomment using rainwater for you plants, if you are able to collect it for the best growing results.
Later i did some research for the dosages with this Hesi coco and have this info for you to try:
For growing:
30ml/10 litres of water.
For the blooming stage:
50ml/10 litres of water.
These dosages are for coco coir of course, so you might want to give a little bit less with the 50:50 coco/soil mix, but adjusting the dosages seem easy enough because it is only one bottle. 
For the soil/coco mix you could try these dosages:
For growing:
10-15ml/10 litres of water.
For the blooming stage:
25ml/10 litres of water.
Thanks for the advice! Indeed I'm looking into possible ways to collect rainwater, but they're generally not the most esthetically pleasing looking things...

But I'll stay away from adjusting pH for now, to see what difference just the new nutes make.
So am I right in assuming that because I have a bit of soil in my pots, it will be better at retaining the various nutrients in the Hesi and therefore should be using lower dosages? I will for sure stick to 25ml/10L for now, and see if going any higher will be worth trying in some weeks.
I also have an overwintered orange hab in my office which must have dropped 100 flowers by now, so hopefully the Hesi nutes will turn this one around too as it has plenty of sunshine and a fan blowing on it at various times of the day to help the pollination - there simply didn't seem to be any pollen on the flowers.
And totally hope you're right about not being able to go wrong with these, your results thus far certainly promise great things!
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